You have to find the red key stone first at the opposite end of the cave then when your inside the red key stone bit you'll find the blue keystone (if tht makes ne sence at all)
but I can't get past tht bit :(

You go to the back of the tea shop.. Then you press 1 to use stealth mode then you make your character face the window and you get the password. Then go to the library. and you get to go inside. -Answer by:janesh